Light emitting diodes are well known in the semiconductor art and generally consist of two layers or more that spontaneously emit light when electric current is applied therethrough. Generally, the color or wavelength of the light emitted is dependent upon the materials used to form the light emitting diode.
Devices commonly referred to as semiconductor lasers have also become well known and popular in recent years. The best known of this group are vertical cavity surface emitting lasers (VCSEL) and edge emitting lasers. Semiconductor lasers generally produce light in response to some stimulation, such as light pumping or electrical pumping. The pumping action is necessary to initiate light emission by the active region and amplification by the mirror stacks. Reflection of the generated light by the mirror stacks further pumps or stimulates the active region so that a lasing action occurs. Generally, the color or wavelength of the light emitted by a semiconductor laser is dependent upon the resonance of the u-cavity and the material used in the active region.
For purposes of differentiation, spontaneous light emission is defined as light generated by simply supplying activating electrical current to a semiconductor junction or active area while stimulated emission occurs when emitted light is enhanced or amplified in a p-cavity and supporting mirror stacks. It will be understood that spontaneous emission is generally much less (i.e. brightness or photoluminescence) than stimulated emission. Because of the difference in the power of emission, spontaneous emitting diodes and the like do not produce sufficient light for communicating at high data rates through optical fibers and in other communication systems.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
Accordingly, it is an object of the present invention to provide a new and improved μ-cavity device capable of relatively high spontaneous or stimulated light emission.
Another object of the invention is to provide a new and improved μ-cavity device capable of sufficient spontaneous light emission for use in communication systems and the like.
Another object of the invention is to provide a new and improved μ-cavity device in which the wavelength of emitted light can be shifted by mirror stacks.